1. Field of the Invention
The present invention relates to a combined structure of optical waveguides used for an optical touch panel or the like. More particularly, the present invention relates to a combined structure in which high combination accuracy is easily obtained.
2. Description of the Related Art
optical waveguides, which are light-weight and capable of carrying out a high-speed signal transmission, have been expected to be utilized as various kinds of electronic devices. Optical touch panels are widely used for bank ATM systems or railway ticket-vending machines and the like because the display screens are clear and excellent in reliability compared with resistive touch panels and capacitance-type touch panels. Optical touch panels in which a large number of light-emitting diodes and phototransistors are arranged around a coordinate input region, are known (Japanese Unexamined Patent Publication No. 11-232024 A). Further, optical touch panels in which optical waveguides and microlenses are provided around the coordinate input region are known (Japanese Unexamined Patent Publication No. 2004-295644 A). The latter optical touch panels using optical waveguides have fewer parts than the former optical touch panels, which leads to easy to reduce the costs. However, the optical touch panels using optical waveguides need alignment of cores to accurately receive light emitted from a core of a light-emitting sided-optical waveguide at a core of a light-receiving sided-optical waveguide. However, in conventional optical touch panels, an alignment between the light-emitting sided-optical waveguide and the light-receiving sided-optical waveguide has been manually performed by repeating minor adjustments, which is a troublesome and time-consuming operation.
In an optical touch panel using an optical waveguide, alignment of cores of a light-emitting sided-optical waveguide and cores of a light-receiving sided-optical waveguide need to be performed to accurately receive light emitted from the cores of the light-emitting sided-optical waveguide (light-emitting sided-cores) at the cores of the light-receiving sided-optical waveguide (light-receiving sided-cores). However, conventionally, to align the cores, the alignment of the light-emitting sided-optical waveguide and the light-receiving sided-optical waveguide has been manually performed while repeating minor adjustments, which is a troublesome and time-consuming operation.